Upright storage cabinets used in offices and similar environments conventionally include an upright hollow cabinet housing which is open at the front and receives one or more file drawers in a vertically stacked arrangement. Such cabinets are well known and typically include a locking mechanism which securely locks each drawer in a closed position.
These locking mechanisms often employ a key-operated lock device which is mounted on a drawer so as to be accessible from a front thereof. The lock device drives an intermediate linkage in the housing that controls vertical movement of a lock bar also supported in the housing. The lock bar cooperates with the individual drawers so as to simultaneously lock the drawers in the closed position when in a locking position and release said drawers when the lock bar is moved vertically to a release position.
Some known cabinets have locking mechanisms which include a lock cam on the lock device which is rotated to drive the intermediate linkage and vertically manipulate the lock bar to move the lock bar between the locking position and the release position. One example of such a cabinet and locking mechanism is the commercially available PREMISE® pedestal storage unit sold by the assignee of the present invention having a family code number of FS49DPFN.
The lock cam of the PREMISE® pedestal unit as illustrated in FIGS. 15-17 includes a lock assembly 100 which is mounted on the front wall of a topmost drawer. The lock assembly 100 includes a lock cam 101 having a generally hemispherically-shaped main body 102 which main body 102 includes a thin-shaped rigid cam portion 103 which projects radially outwardly from an outer surface of the main body 102 and terminates in a straight edge 104 at the distal end thereof. On a rearward facing side of the main body 102, a circular opening 106 is defined therein which projects forwardly into the main body 102 and terminates at a flat base wall 107. As shown in FIG. 16, the base wall 107 includes a vertically-elongate rectangular slot 110 which opens into a generally circular recess 111 which said recess 111 is defined in the frontward facing side of the main body 102.
The lock assembly 100 additionally includes a cylindrically shaped lock shell 112 which is non-rotatably mounted on the front wall of the cabinet drawer. The lock shell 112 defines a receptacle 113 which opens forwardly and is adapted to receive a plug-type actuator 121 (illustrated in phantom outline in FIG. 17). The actuator 121 is a key-type actuator which is operated by a key 122 (FIG. 15) to lock and unlock the lock assembly 100 through rotation of the lock cam 103.
The lock assembly 100 further includes a generally rectangular insert or lug 114 that is mounted to said actuator for rotation within the lock shell 112. The lug 114 includes an internally threaded hole 115 for receiving a pinch bolt or screw 116 which said screw 116 is engaged with the threaded hole 115 to fasten the lock cam 103 to the lock shell 112. In this regard, the screw head 117 is located within the cam hole 106 on the rearward side of the cam base wall 107 such that the screw head 117 clamps the base wall 107 along the longitudinal edges of the rectangular slot 110. The screw 116 thereby fixes the cam member 101 on the lug 114 and due to the rectangular shape of the lug 114, the cam 103 rotates in unison with the lug 114.
More particularly, the lug 114 includes an annular plate 120 which is non-rotatably fixed to lug 114 and cooperates with the lock shell 112 to prevent rotation of the lug 114 relative to the lock shell 112. In this regard, the plate 120 includes a notch on the periphery thereof which defines a pair of shoulders (not shown) which are circumferentially spaced apart from one another and cooperate with a corresponding stop (not shown) on the rearmost end of the lock shell 112.
Thus, when locking of the drawers is desirable, the key 122 is inserted into the actuator 120 and turned which thereby rotates the lug 114 and associated lock cam 101 between locked and unlocked positions which positions are defined by the shoulders of plate 120 with the stop on the lock shell 112. Rotation of the cam 101 causes the edge 104 thereof to make contact with a horizontal drive element or shaft which extends along the upper frontmost edge of the cabinet housing. Rotation of the drive element by cam portion 103 in turn raises a vertical locking bar oriented along a side wall of the cabinet. The vertical locking bar cooperates with the individual drawers to lock same in the closed position or release the drawers for opening thereof by vertical displacement of the locking bar.
Since the lug 114 may be slid vertically and thereby adjusted within the vertically elongate slot of the cam 101, the cam 101 tends to undergo “creep” or undesirable sliding within the slot 110 over a period of time. That is, repeated use of the lock assembly 100, movement of the cabinet, etc., can cause the cam 101 to shift longitudinally within the slot 110 from its original installed position. This shifting of the cam member 103 often results in a misalignment of the cam 103 relative to the drive element. Such creep of the cam body 101 from this installed position typically causes malfunctioning of the lock assembly 100 which in turn necessitates time consuming and costly readjustment of the position of the cam body 101.
It is an object of the present invention to overcome the disadvantages associated with the lock assembly 100 and undesirable creep or shifting of the cam body 101 referenced above. The invention relates to an improved lock assembly which has a cam body that is fixed on said lug 114 which eliminates undesirable creep or shifting of the cam body. To accommodate changes in the relative distance between the cam body and a horizontal drive element which differences may result from variations in manufacturing tolerances, wear or the like, the cam body includes a resilient cam projecting radially outwardly therefrom. The cam is resiliently deflectable radially inwardly which automatically compensates for manufacturing tolerances and wear without any adjustments being required in the connection of the cam body with the lug on the lock assembly.
Other objects and purposes of the invention, and variations thereof, will be apparent upon reading the following specification and inspecting the accompanying drawings.
Certain terminology will be used in the following description for convenience in reference only, and will not be limiting. For example, the words “upwardly”, “downwardly”, “rightwardly” and “leftwardly” will refer to directions in the drawings to which reference is made. Further, the words “frontwardly” and “rearwardly” will respectively refer to the side of the storage cabinet which normally faces the user and the side of the cabinet which normally faces away from the user. The words “inwardly” and “outwardly” will refer to directions toward and away from, respectively, the geometric center of the arrangement and designated parts thereof. Said terminology will include the words specifically mentioned, derivatives thereof, and words of similar import.